This invention relates to a method for detecting abnormal morphology of erythrocytes by the use of optical means.
Observing the morphology of erythrocytes in the blood is useful for obtaining valuable information for diagnosis of various diseases. Elliptocytes, for example, are noted in hereditary elliptocytosis, iron deficiency anemia and megaloblastic anemia. Echinocytes mostly occur after blood sampling, but are observed rarely in uremia. Dacryocytes are seen in myelofibrosis, myelic metastasis of cancer, and thalassemia. Schizocytes appear in DIC (disseminated intravascular coagulation), uremia, and microvascular hemolytic anemia. Anisocytosis develops in various anemias. Other abnormal forms of erythrocyte include sickle cell, holly leaf form, etc.
Various blood cell counters are commercially available now. Their principles of counting are roughly classified into the electric resistance system and the optical system. A number of automatic blood cell counters can not only count blood cells, but also measure the hemoglobin concentration. They are also able to supply information on the particle size distribution of blood cells. Some counters determine whether blood samples are normal or abnormal, by the measurements of these plural parameters in accordance with the determination equation. Based on the determinations, these counters display an abnormality message in case of abnormal findings, or a suspect message if any disease or abnormality is suspected.
Messages from blood cell counters that show abnormalities in the red cell system are merely concerned with abnormalities in the count, abnormalities in the size, and abnormalities in the hemoglobin concentration of erythrocytes. When MCHC (mean cell hemoglobin concentration) exceeds 36.5 g/dl, spherocytosis is suspected. If the particle size distribution intermediate between erythrocytes and thrombocytes is abnormal, the appearance of schizocytes is suspected. Other states of abnormal morphology cannot be suggested by suspect messages issued based on the measurements.